Aaron Mittelstet, Ph.D.

Aaron Mittelstet

Contact Information:

East Campus (Lincoln)
245 L.W. Chase Hall

Watershed Hydrologist, Assistant Professor, Robert B. Daugherty Water For Food Institute Fellow

Academic Degrees

  • Ph.D., Biosystems and Agricultural Engineering, Oklahoma State University, 2015
  • M.S., Environmental Science, Oklahoma State University, 2009
  • B.S., Zoology, Oklahoma State University, 2000

Current Graduate Students

Galen Richards (co-advised with Dr. Troy Gilmore), M.S. School of Natural Resources, Expected Graduation: July 2020; Research Topic: Survey of Groundwater Transit Times and Nitrate Delivery to Bazile Creek

Nawaraj Shrestha, PhD School of Natural Resources, Expected Graduation: July 2021; Research Topics: Exploring Hypothetical Correlation Between Drought and Lake Area of Groundwater-fed Lakes in Western Sandhills; Quantifying the Encroachment of Eastern Red Cedar in the Nebraska Sandhills

Yaser Kishawi, PhD Biological Systems Engineering, Expected Graduation: December 2021; Research Topics: Quantifying the Impact of Eastern Red Cedar Encroachment on Water Resources in the Nebraska Sandhills and Platte River

Caner Zeyrek (co-advised with Dr. Troy Gilmore), PhD School of Natural Resources, Expected Graduation: December 2021; Research Topics: Evaluation of Watershed-Scale Groundwater Transit Time Distributions from Field Sampling and Numerical Modeling 

Griffen Nuzzo (co-advised with Dr. Troy Gilmore), PhD School of Natural Resources, Expected Graduation: May 2023; Research Topics: Water Resources in the Nebraska Sandhills

Past Graduate Students

Jessie Johnson, M.S. Biological Systems Engineering,  Graduation date: May 2020; Research Topic: Application of an ultrasonic sensor to monitor soil erosion and depostion and implications for improving resilience, policy and outreach in riparian ecosystems. Currently employed with NRCS in Holdridge, NE.

Jess Satiroff (co-advised with Dr. Tiffany Messer), M.S. Environmental Engineering, Biological Systems Engineering, Graduation date: July 2020; Thesis Topic: Pesticide occurence and persistence entering recreational lakes residing in watersheds of various land uses.

Matt Russell, M.S. School of Natural Resources, Graduation date: May 2020; Thesis Title: Impact of streambank stabilization on sediment depostion and erosion in central Nebraska. Currently PhD student in Biological Systems Engineering at UNL, Lincoln, NE.

Olufemi Abimbola, PhD Biological Systems Engineering, Expected Graduation: December 2019; Dissertation Title: Modeling streambed vertical hydraulic conductivity, water quality pollutants, and best management practices using machine learning and the soil and water assessment tool. Currently post-doc in School of Natural Resources at UNL, Lincoln, NE.

Naisargi Dave, M.S. Environmental Engineering, Biological Systems Engineering, Graduation date: July 2018; Thesis Title: Evaluation of Effectiveness of Streambank Stabilization Practices and Flood Impact on Cedar River, Nebraska. Currently employed with Water for Food Institute in Lincoln, NE.


  • 60% Research
  • 40% Teaching

Curriculum Vitae (CV):

Areas of Research and Professional Interest

  • Watershed Modeling
  • Surface/Ground Water Interaction
  • Water Quality
  • Streambank Erosion

Courses Taught

About Aaron Mittelstet

Aaron Mittelstet became an Assistant Professor of Biological Systems Engineering in January 2016. He teaches courses within BSE and advises undergraduate, graduate, and Ph.D. students. Mittelstet is also a courtesy Assistant Professor within the School of Natural Resources and serves as a fellow for the Robert B. Daugherty Water for Food Institute.

Mittelstet has published several publications over the years and earned numerous grants for his research. His interests are in the areas of watershed modeling, surface/groundwater interaction, water quality, and streambank erosion.  

Mittelstet advises the UNL Fountain Wars Design Team. Fountain Wars is a hands-on competition in which a team of up to six students design a fountain to complete challenges using the necessary PVC pipes, couplers, fittings, valves, nozzles, and pumps.

He earned his Ph.D. in Biosystems and Agricultural Engineering; his M.S. in Environmental Science; and his B.S. in Zoology all from Oklahoma State University.

Honors and Awards

  • 2020 ASABE Superior Paper award
  • 2018 UNL College of Engineering Recognition for Highly Impactful Research
  • M.S. student Naisargi Dave won 1st Place at the 2017 Water for Food Conference Poster Contest
  • 2nd Place, Student Poster Contest, 23rd Annual Oklahoma Clean Lakes and Watersheds Association Conference, Stillwater, OK, 2014.
  • Outstanding Manuscript Reviewer Award, ASABE, 2013.
  • 3rd Place, Student Poster Contest,  OWRRI Oklahoma Water Research Symposium, Midwest City, OK, 2013.
  • 2nd place, Environmental Science Graduate Paper Presentation, OWRRI Oklahoma State Water Research Symposium, Stillwater, OK, 2011.
  • Jimmie Pigg Environmental Policy Research Assistantship, 2009.



  1. “Evaluation of Watershed-scale Groundwater Transit Time Distributions from Field Sampling and Numerical Modeling.” Sponsor: National Science Foundation. PI: T. Gilmore (50%) Co-PI: A.R. Mittelstet (40%), V. Zlotnik (10%). Sponsor Amount: $880,944; UNL: $387,030.
  2. “Quantifying the Effects of Eastern Red Cedar Encroachment on Recharge in the Nebraska Sandhills” (Jan. 2018-Dec. 2021). Sponsor: Water Sustainability Fund. PI: A.R. Mittelstet (60%); Co-PI: C. Neale (20%); Craig Allen (10%); Dirac Twidwell (10%). Sponsor Amount:  $144,716.
  3. “Plan for Region Ephemeral Gully Erosion” (January 2020 to December 2020). Sponsor: USDA-NRCS. PI: T. Franti (55%) Co-PI: A.R. Mittelstet (15%), W. Woldt (15%), P. Jasa (15%). Sponsor Amount: $66,486
  4. “Survey of Groundwater Transit Times and Nitrate Delivery to Bazile Creek” (June 2018 – May 2020). Sponsor: Department of Environmental Quality. PI: T.G. Gilmore (50%); Co-PI: A.R. Mittelstet (40%); T.L. Messer (10%). Sponsor Amount:  $30,000.
  5. “Quantifying Cost-Efficiency of Streambank Stabilization Practices on Cedar River” (Apr. 2018-Mar. 2020). Sponsor: Nebraska Environmental Trust. PI: A.R. Mittelstet (92%); Co-PI: Lower Loup RC&D (8%). Sponsor Amount:  $92,849.


  1. “Quantifying the Effects of Eastern Red Cedar Encroachment on Recharge in the Nebraska Sandhills” (August 2018 to July 2021). Sponsor: Water for Food Institute (WFI) Grad Student Research Support. PI: A.R. Mittelstet (100%). Sponsor Amount: $96,746.
  2. “Integrating Hydrological Modeling and Characterization Approaches across Scales to Understand the Effects of Efficient Irrigation Management on Groundwater/Surface Water Systems” (March 2018 to October 2022). Sponsor: Approved Hatch project (UNL Agricultural Research Division and USDA National Institute of Food and Agriculture). PI: A. R. Mittelstet (20%); Co-PI: D. Rudnick (20%); T. Gilmore (20%); J. Korus (20%); X. Qiao (20%). Sponsor Amount: $0. 
  3. “LTAR Research: Testing a Novel Groundwater Age-dating Technique in the Bazile Creek Watershed” (November 2019 to October 2020). Sponsor: USDA. PI: T. Messer (50%); Co-PI: T. Gilmore (30%); A. R. Mittelstet (20%). Sponsor Amount: $33,648.

Selected Publications

  1. Beni, N.N, D. Snow, E.D. Berry, A.R. Mittelstet, T.L. Messer and S. Bartelt-Hunt. 2020. Measuring the occurrence of antibiotics in surface water adjacent to cattle grazing areas using passive sampler. Science of the Total Environment. Accepted. 
  2. Abimobla, O.P., A.R. Mittelstet, T.L. Messer, E.D. Berry, S. Bartelt-Hunt and S. Hansen. 2020. Predicting Escherichia coli loads in cascading dams with machine learning: An integrating of hydrometeorology, animal density and grazing patterns. Science of the Total Environment 722(20). 
  3. Abimbola, O., A.R. Mittelstet, T.E. Gilmore and J.K. Korus. 2020. Influence of watershed characteristics on streambed hydraulic conductivity across multiple stream orders. Nature Scientific Reports. 10(1): 1-10. 
  4. Cherry, M., T.E. Gilmore, A.R. Mittelstet, D. Gastmans, J. Gates. 2020. Isotopic composition of groundwater and precipitation in Nebraska, USA. Hydrological Processes. 
  5. Dave, N., A.R. Mittelstet, J. Korus and M. Waszgis. 2020. Impact of an extreme flood event on streambank retreat on Cedar River, Nebraska. Journal of the American Water Resource Association. 
  6. Hansen, S., T. Messer, A.R. Mittelstet, E.D. Berry, S. Bartelt-Hunt and O. Abimbola. 2020. Escherichia coli concentrations in waters of a reservoir system impacted by cattle grazing and migratory waterfowl. Science of the Total Environment 705(25). 
  7. Gilmore, T.E., M. Johnson, J. Korus, A.R. Mittelstet and M. Briggs. 2019. Streambed flux measurement informed by distributed temperature sensing leads to significantly different characterization of groundwater discharge. Water. 11(11):2312. 
  8. Keilhauer, M.G., T.L. Messer, A.R. Mittelstet, J.R. Corman and T.G. Franti. 2019. Nitrate removal potential of floating treatment wetlands amended with spent coffee: A mesocosm scale evaluation. Transactions of the ASABE
  9. Hansen, S., T.L. Messer and A.R. Mittelstet, 2019. Mitigating the risk of atrazine exposure across Nebraska, USA: Identifying hot spots and hot times in surface water watersheds. Journal of Environmental Management. 250:1-11. 
  10. Mittelstet, A.R., T.E. Gilmore, T. Messer, D.R. Rudnick and T. Heatherly, 2019. Evaluation of watershed characteristics to identify best management practices to reduce Nebraskan nitrate loads to the Mississippi/Atchafalaya River Basin. Agriculture, Ecosystem and the Environment. 277:1-10.